High-power-density SCR device structure and semiconductor device
By introducing a metal filling area in the SCR device to connect the N-type area and the P-type area, a larger current discharge path is formed, which solves the problem of insufficient ESD current discharge capacity without increasing the device area in the existing technology, and achieves higher current discharge capacity and current uniformity.
Patent Information
- Application Number
- CN202422606652.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-10-28
AI Technical Summary
Existing SCR devices are difficult to improve their ESD current discharge capabilities without increasing the device area, resulting in challenges in chip miniaturization and convenience.
By introducing a metal filling region between the P-type region and the N-type region, the N-type region and the P-type region are directly connected, forming a larger effective current discharge path and enhancing the current discharge capability of the SCR device.
Without increasing the device area, the current discharge capacity and current uniformity of the SCR device are significantly improved, and the maximum transient pulse power that can be tolerated per unit area is increased.
Smart Images
Figure CN223348994U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semiconductor power devices, mainly to electrostatic discharge (ESD) protection technology, and specifically to an SCR (Silicon Controlled Rectifier) device structure and a semiconductor device with high power density. Background Art
[0002] ESD, or electrostatic discharge, is a ubiquitous phenomenon in nature. ESD is present in every aspect of our daily lives. However, this commonplace electrical phenomenon can pose a fatal threat to precision integrated circuits. For packaged chips, the power, input, and output pins become pathways for pulse currents such as those measured by the Human Body Model (HBM), Machine Model (MM), and Human Metal Model (HMM). Strong ESD pulses can not only cause hard failures in chips but can also trigger various effects (such as latch-up and soft leakage) caused by improperly designed ESD protection components. Furthermore, only a very small number of ESD failures can be directly detected during the chip manufacturing process. Most ESD damage does not significantly affect chip performance, allowing it to pass standard testing and ultimately reach customers. These chips, operating despite the defect in various applications, pose a constant threat to the reliability of the systems they are used in.
[0003] SCR is a commonly used ESD protection device. Its device structure is as follows: Figure 1 As shown in Figure 2. Due to its unique PNPN structure, the device experiences strong hysteresis after triggering, resulting in high current robustness. However, for conventional lateral SCR devices, the ability to discharge transient pulse current is proportional to the areas of the P+ and N+ junctions. To enhance the ESD current discharge capability of SCR devices, the device area must be increased to obtain a larger effective current discharge channel. This poses a significant challenge to the miniaturization and portability of modern integrated electronic systems.
[0004] It should be noted that the information disclosed in the background technology section of this utility model is only intended to deepen the understanding of the general background technology of the utility model, and should not be regarded as an admission or in any form of implication that the information constitutes prior art already known to those skilled in the art. Utility Model Content
[0005] The purpose of the present utility model is to provide a high-power density SCR device structure and semiconductor device to solve the problem of how to improve the SCR device's ability to discharge ESD current and increase the maximum transient pulse power that the ESD device can withstand per unit area by improving the SCR device structure and manufacturing process without increasing the device area.
[0006] In order to solve the above technical problems, the present invention provides a high power density SCR device structure, comprising:
[0007] substrate;
[0008] An N-type well region is formed in the substrate, with a P-type well region adjacent to one side of the N-type well region;
[0009] A first metal filling region is provided in the N-type well region, wherein a first N-type region and a first P-type region are provided on both sides of the first metal filling region respectively;
[0010] The second metal filling region is arranged in the P-type well region, and a second N-type region and a second P-type region are respectively arranged on both sides of the second metal filling region.
[0011] Preferably, the bottom of the first metal-filled region is higher than the bottom of the first N-type region and the bottom of the first P-type region.
[0012] Preferably, the first N-type region is L-shaped, one side of the first metal filling region is connected to the first N-type region, and a portion of the first N-type region is provided at the bottom.
[0013] Preferably, the first P-type region is in an inverted L-shape, the other side of the first metal filling region is connected to the first P-type region, and a portion of the first P-type region is provided at the bottom.
[0014] Preferably, the first N-type region and the first P-type region are separated by at least a portion of the N-type well region.
[0015] Preferably, the bottom of the second metal-filled region is higher than the bottom of the second N-type region and the bottom of the second P-type region.
[0016] Preferably, the second N-type region is L-shaped, one side of the second metal filling region is connected to the second N-type region, and a portion of the second N-type region is provided at the bottom.
[0017] Preferably, the second P-type region is in an inverted L-shape, the other side of the second metal filling region is connected to the second P-type region, and a portion of the second P-type region is provided at the bottom.
[0018] Preferably, the second P-type region and the second N-type region are separated by at least a portion of the P-type well region.
[0019] The utility model provides a semiconductor device, which adopts the high power density SCR device structure as mentioned above.
[0020] In the high-power-density SCR device structure provided by the present invention, a metal-filled region is used to connect the N-type region and the P-type region in the well region. Current is discharged from the first metal-filled region to the first P-type region and finally flows to the second N-type region. By introducing the metal-filled region, the SCR device structure can have a larger effective current discharge path area, thereby improving the current uniformity of the SCR device under high current. As a result, the high-power-density SCR device structure proposed by the present invention can significantly improve the device's discharge current capability without increasing the device area, thereby increasing the maximum transient pulse power that the SCR device can withstand per unit area.
[0021] The semiconductor device provided by the present invention and the high power density SCR device structure provided by the present invention belong to the same technical concept. Therefore, the semiconductor device provided by the present invention has at least all the advantages of the high power density SCR device structure provided by the present invention, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.
[0023] Figure 1 It is a schematic diagram of the cross-sectional structure of a traditional SCR device;
[0024] Figure 2 This is a schematic cross-sectional view of a high power density SCR device according to an embodiment of the present invention;
[0025] Figure 3 This is a schematic diagram of the substrate structure of another embodiment of the present invention;
[0026] Figure 4 This is a schematic structural diagram of an N-type well region and a P-type well region in another embodiment of the present invention;
[0027] Figure 5 This is a schematic diagram of the groove structure of another embodiment of the utility model;
[0028] Figure 6 It is a schematic structural diagram of the ion implantation region of another embodiment of the present invention.
[0029] In the attached figure:
[0030] 101, substrate; 201, N-type well region; 202, P-type well region; 301, first N-type region; 302, second N-type region; 401, first P-type region; 402, second P-type region; 501, first metal filling region; 502, second metal filling region. DETAILED DESCRIPTION
[0031] To further clarify the objectives, advantages, and features of the present invention, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are highly simplified and not drawn to scale, and are intended solely to facilitate and clearly illustrate the objectives of the embodiments of the present invention. Furthermore, the structures shown in the drawings are often portions of the actual structures. In particular, different drawings may require different emphases and may use different scales.
[0032] As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of such features. The term "proximal end" generally refers to the end closest to the operator, and the term "distal end" generally refers to the end closest to the patient. "One end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only endpoints. The terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be internal communication between two elements or an interaction relationship between two elements. In addition, as used in the present invention, an element is generally provided on another element, which generally only means that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements can be direct or indirect through an intermediate element, and it cannot be understood to indicate or imply a spatial positional relationship between the two elements, that is, one element can be in any position such as inside, outside, above, below, or to the side of another element, unless the content clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.
[0033] The inventors have found that the ESD current discharge capability of an SCR device is generally proportional to the areas of the P+ junction and the N+ junction. It is difficult to achieve a good current discharge capability under the condition of a smaller device area.
[0034] Based on this, the core idea of the present invention is to introduce a metal filling area between the P-type area and the N-type area, so that the P-type area and the N-type area in the metal filling area are directly connected, thereby significantly increasing the effective current path area of the SCR device for discharging ESD current, improving the current uniformity of the SCR device under large current, and increasing the maximum transient pulse power that the ESD device can withstand per unit area.
[0035] For details, please refer to Figure 2 , which is a schematic diagram of an embodiment of the present utility model. Figure 2 As shown, a high power density SCR device structure includes:
[0036] substrate 101;
[0037] An N-type well region 201 is formed in the substrate 101 , with a P-type well region 202 adjacent to one side of the N-type well region 201 ;
[0038] A first metal filling region 501 is provided in the N-type well region 201 , wherein a first N-type region 301 and a first P-type region 401 are provided on both sides of the first metal filling region 501 ;
[0039] The second metal filling region 502 is disposed in the P-type well region 202 . The second N-type region 302 and the second P-type region 402 are disposed on both sides of the second metal filling region 502 .
[0040] When an ESD transient event occurs, the reverse biased PN junction formed by the N-type well region 201 and the P-type well region 202 breaks down, and the resulting breakdown current flows through the parasitic resistance of the N-type well region 201 and the P-type well region 202 to generate a voltage drop, causing the parasitic NPN and PNP transistors in the SCR structure to turn on and couple with each other to form positive feedback, thereby discharging the ESD current. After the SCR device is triggered, the main current discharge path is the first P-type region 401-N-type well region 201-P-type well region 202-second N-type region 302, introducing the first metal filling region 501 and the second metal filling region 502. The first metal filling region 501 and the second metal filling region 502 are used to lead out two ports to discharge current. The two sides of the first metal filling region 501 are respectively connected to the second metal filling region 502. An N-type region 301 and a first P-type region 401 are formed, and the second metal filling region 502 is connected to the second N-type region 302 and the second P-type region 402 on both sides. The metal filling region is used to connect the N-type region and the P-type region in the well region. The current is discharged from the first metal filling region 501 to the first P-type region 401 and finally flows to the second N-type region 302. By introducing the metal filling region, the SCR device structure can have a larger effective current discharge path area, thereby improving the current uniformity of the SCR device under high current. Therefore, the high power density SCR device structure proposed by the utility model can significantly improve the device's discharge current capability without increasing the device area, thereby increasing the maximum transient pulse power that the SCR device can withstand per unit area.
[0041] like Figure 2 As shown, N-type well region 201 is located on the upper left side of substrate 101, with the upper edge of N-type well region 201 tangent to the upper edge of substrate 101. P-type well region 202 is located on the upper right side of substrate 101, with the upper edge of P-type well region 202 tangent to the upper edge of substrate 101. N-type well region 201 and P-type well region 202 are adjacent to each other, with the right edge of N-type well region 201 tangent to the left edge of P-type well region 202. In actual use, two ports are drawn from first metal filling region 501 and second metal filling region 502 through external contact holes and metal, respectively, to discharge ESD current.
[0042] In one embodiment, the bottom of the first metal-filled region 501 is higher than the bottom of the first N-type region 301 and the bottom of the first P-type region 401. More preferably, the first N-type region 301 is L-shaped, with one side of the first metal-filled region 501 connected to the first N-type region 301 and a portion of the first N-type region 301 disposed at the bottom.
[0043] More preferably, the first P-type region 401 is in an inverted L-shape, the other side of the first metal filling region 501 is connected to the first P-type region 401, and a portion of the first P-type region 401 is provided at the bottom, and the first N-type region 301 and the first P-type region 401 are separated by at least a portion of the N-type well region 201.
[0044] The L-shaped first N-type region 301, the first metal filling region 501, and the inverted L-shaped first P-type region 401 are located above the interior of the N-type well region 201, and the upper edges of the three are tangent to the upper edge of the N-type well region 201; the L-shaped first N-type region 301, the first metal filling region 501, and the inverted L-shaped first P-type region 401 are closely arranged from left to right, and the bottom of the first N-type region 301 and the bottom of the first P-type region 401 are separated by the N-type well region 201.
[0045] In one embodiment, the bottom of the second metal-filled region 502 is higher than the bottom of the second N-type region 302 and the bottom of the second P-type region 402. More preferably, the second N-type region 302 is L-shaped, with one side of the second metal-filled region 502 connected to the second N-type region 302 and a portion of the second N-type region 302 disposed at the bottom.
[0046] More preferably, the second P-type region 402 is in an inverted L-shape, the other side of the second metal filling region 502 is connected to the second P-type region 402, and a portion of the second P-type region 402 is provided at the bottom, and the second P-type region 402 and the second N-type region 302 are separated by at least a portion of the P-type well region 202.
[0047] The L-shaped second N-type region 302, the second metal-filled region 502, and the inverted L-shaped second P-type region 402 are located above the interior of the P-type well region 202, and the upper edges of the three are tangent to the upper edge of the N-type well region 201; the L-shaped second N-type region 302, the second metal-filled region 502, and the inverted L-shaped second P-type region 402 are closely arranged from left to right, and the bottom of the second P-type region 402 and the bottom of the second N-type region 302 are separated by the P-type well region 202.
[0048] Based on the same technical concept, the present disclosure also provides a semiconductor device, which adopts the high power density SCR device structure as described above.
[0049] Based on the same technical concept, the present disclosure also provides a method for manufacturing a high power density SCR device structure, comprising the following steps:
[0050] S1, providing a substrate 101, such as Figure 3As shown, the substrate 101 referred to herein may include any type of substrate, typically a semiconductor substrate, such as a bulk single crystal silicon wafer, a binary compound substrate (e.g., a GaAs silicon wafer), a ternary compound substrate (e.g., AlGaAs), or a higher order compound silicon wafer, on which an additional insulating layer or conductive layer may or may not be formed. When a semiconductor substrate is used, it may also include non-semiconductor materials, such as oxides in a semi-silicon wafer (SOI), a portion of an SOI substrate, polycrystalline silicon, an insulator, oxides, metals, amorphous silicon, or organic materials.
[0051] S2, ion implantation is performed in the substrate 101 to form adjacent N-type well region 201 and P-type well region 202, as shown in FIG. Figure 4 For example, an N-type well region 201 and a P-type well region 202 are formed adjacent to each other through ion implantation and thermal well pushing.
[0052] S3, etching a first trench and a second trench in the N-type well region 201 and the P-type well region 202 respectively, as shown in FIG. Figure 5 shown.
[0053] S4, ion implantation is performed at a certain angle to the inner walls of the first trench and the second trench, respectively, to form a first N-type region 301 and a first P-type region 401 on both sides of the first trench, respectively, and a second N-type region 302 and a second P-type region 402 on both sides of the second trench, respectively. Figure 6 The first N-type region 301 , the first P-type region 401 , the second N-type region 302 and the second P-type region 402 are formed by tilted ion implantation and thermal activation.
[0054] Specifically, performing ion implantation at a certain angle into the inner walls of the first trench and the second trench includes implanting ions into the first side and a portion of the bottom of the first trench and the first side and a portion of the bottom of the second trench to form L-shaped first N-type region 301 and second N-type region 302.
[0055] Specifically, performing ion implantation at a certain angle into the inner walls of the first trench and the second trench includes: performing ion implantation into the second side and part of the bottom of the first trench and the second side and part of the bottom of the second trench to form an inverted L-shaped first P-type region 401 and a second P-type region 402.
[0056] S5, filling the first trench and the second trench with metal, such as Figure 2 shown.
[0057] When an ESD transient event occurs, the reverse-biased PN junction formed by the N-type well region 201 and the P-type well region 202 breaks down, and the resulting breakdown current flows through the parasitic resistance of the N-type well region 201 and the P-type well region 202 to generate a voltage drop, causing the parasitic NPN and PNP transistors in the SCR structure to turn on and couple with each other to form positive feedback, thereby discharging the ESD current. After the SCR device is triggered, the main current discharge path is the first P-type region 401-N-type well region 201-P-type well region 202-second N-type region 302, introducing the first metal filling region 501 and the second metal filling region 502. The first metal filling region 501 and the second metal filling region 502 are used to lead out two ports to discharge current. The two sides of the first metal filling region 501 are respectively connected to the first N-type region 301 and the first P-type region 401, and the two sides of the second metal filling region 502 are respectively connected to the second N-type region 301 and the first P-type region 401. The N-type region 302 and the second P-type region 402 are connected to the N-type region and the P-type region in the well region through the metal filling region. The current is discharged from the first metal filling region 501 to the first P-type region 401 and finally flows to the second N-type region 302. The high-power density SCR device structure provided by the present disclosure uses a deep trench etching process and an inclined ion implantation process to form deeper "L-shaped" and "flipped L-shaped" heavily doped N-type region and heavily doped P-type region without increasing the device occupied area. This can enable the SCR device structure to have a larger effective current discharge path area, improve the current uniformity of the SCR device under high current, so that the high-power density SCR device structure proposed by the utility model can significantly improve the device's discharge current capability without increasing the device area, and increase the maximum transient pulse power that the SCR device can withstand per unit area.
[0058] The above description is only a description of the preferred embodiment of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the technical solution of the present invention.
Claims
1. A high power density SCR device structure, characterized in that: include: substrate; An N-type well region is formed in the substrate, with a P-type well region adjacent to one side of the N-type well region; A first metal filling region is provided in the N-type well region, wherein a first N-type region and a first P-type region are provided on both sides of the first metal filling region respectively; The second metal filling region is arranged in the P-type well region, and a second N-type region and a second P-type region are respectively arranged on both sides of the second metal filling region.
2. The high power density SCR device structure according to claim 1, characterized in that: The bottom of the first metal-filled region is higher than the bottom of the first N-type region and the bottom of the first P-type region.
3. The high power density SCR device structure according to claim 2, characterized in that: The first N-type region is L-shaped, one side of the first metal filling region is connected to the first N-type region, and a portion of the first N-type region is disposed on the bottom.
4. The high power density SCR device structure according to claim 2, characterized in that: The first P-type region is in an inverted L-shape, the other side of the first metal filling region is connected to the first P-type region, and a portion of the first P-type region is provided at the bottom.
5. The high power density SCR device structure according to claim 2, characterized in that: The first N-type region and the first P-type region are separated by at least a portion of the N-type well region.
6. The high power density SCR device structure according to claim 1, characterized in that: The bottom of the second metal-filled region is higher than the bottom of the second N-type region and the bottom of the second P-type region.
7. The high power density SCR device structure according to claim 6, characterized in that: The second N-type region is L-shaped, one side of the second metal filling region is connected to the second N-type region, and a portion of the second N-type region is disposed on the bottom.
8. The high power density SCR device structure according to claim 6, characterized in that: The second P-type region is in an inverted L-shape, the other side of the second metal filling region is connected to the second P-type region, and a portion of the second P-type region is provided at the bottom.
9. The high power density SCR device structure according to claim 6, characterized in that: The second P-type region and the second N-type region are separated by at least a portion of the P-type well region.
10. A semiconductor device, characterized in that: The high power density SCR device structure according to any one of claims 1 to 9 is adopted.